Oiling Putin’s War?

File on 4 investigates the secretive world of oil shipping, dark fleets and camouflaged cargos. Sanctions were supposed to hit President Putin in the pocket, weakening his military capabilities. But have they simply created new markets and new millionaires? And why can a company in Essex enable Russian oil to move around the world without attracting the attention of the authorities? Reporter: Paul Kenyon Producer: Jo Casserly Editor: Carl Johnston